The Digital Subscriber Line (DSL) technique is a high-speed transmission technique that transmits data over a telephone twist pair, i.e., Unshielded Twist Pair (UTP), and may include the following techniques: an Asymmetrical Digital Subscriber Line (ADSL), a Very-high-bit-rate Digital Subscriber Line (VDSL), an Integrated Services Digital Network (ISDN)-based Digital Subscriber Line (IDSL), a Single-pair High-bit-rate Digital Subscriber Line (SHDSL), an Asymmetrical Digital Subscriber Line 2 (ADSL2), an Asymmetrical Digital Subscriber Line 2plus (ADSL2plus), a Very-high-bit-rate Digital Subscriber Line 2 (VDSL2), etc.
With the gradual expansion of the scale of a network of Digital Subscriber Line Access Multiplexers (DSLAM), applications of the DSLAM network face problems with regards to quick subscriber cable selection, accurate fault location, and automatic periodic line maintenance. At the initial stage for deploying the DSLAM network, services fulfillment in small-scale network may be maintained manually. However, with the gradual expansion of the scale of the DSLAM network, testing and maintaining the twist pair merely on a manual basis does not meet the developing demand of the DSLAM network. Thus the problem regarding the test and maintenance of twist pairs has become a bottleneck of the large-scale development of the DSLAM network.